Relay



April 6 1926.

E.J.PRATT RELAY Filed Sept. 9, 1924 2 Sheets-Sheet l April 6 1926.

,579,887 E. J. PRATT RELAY Filed Sept. 9, 1924 2 Sheets-Sheet g Patented Apr. 6, 1926,

UNITED STATES PATENT. OFFIC 1 EDWARD JACOB PRATT, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECI'fiIC COM- rm, H'COBPORATED, OF NEW YORK, N. Y.,'A CORPORATION OFN'EW YORK.-

RELAY. u

Application filed September 9, 1924. Serial 1T0. 796,693.

To all whom it may conccm:

Be it known that I, EDWARD JACOB PRA'I'I, a citizen of theUnited States of America, residing at New York, inthe county of New York, State of New York, have invented certain new and useful Improvements in Relays, of which the following is a full, clear, concise, and exact description.

Thisinvention relates to relays, and more particularly to alternating current relays for controlling electrical circuits.

r The object of this invention is to provide an improved relay of this character, wherein the energization of a coil or a plurality of coils. positioned in a magnetic field, serves to actuate an armature having'an associated loose contact dev ce which in turn controls a circuit arrangement.

tact device to o A feature of the invention resides in the provision'of a cross pole magnetic structure similar to that disclosed in a copending ap-- plication, Serial No. 678,935, tiled December 6, 1923 each pole of which is provided with two polar extensions projectin on opposite sides of each pole, which in eiiect form two sets of north and south poles; one, set of.

north and south polar extensions being positioned oppositely to the other set. Rigidly positioned between these polar extensions is a coil adapted to be connected to a source of alternating current. An adjustable reed armature passes through the center of the coil and supports one end of a loose contact device similar to that shown in copending application, Serial No. 715,002, filed May 22,1924. When the coil is energized by alcurrent, it causes the loose conternating nits contacts which may control a IOCflTCllClllt.

Another feature of theinve'ntion resides in the provision of a relay having a plurality of coils, one being located in ear: of the branches of an alternating current flux cir-- cuit and arranged, when'energized' by alternating current, to actuate a reed armature in accordance with the frequency of the applied alternating current. The motion of said reed'armature-is utilized to operate a invention may loose contact device similar to that previous ly mentioned which in turn may control an electrical circuit.

These and numerous other features of this be understood from the following description and the accompanying 7 drawing, Fig. 1 of which represents a relay' parent in Fig. 1. Similar components of the relay are similarly marked in the difi'erent figures. Fig. 4 1s a perspective of the lcross. pole construction employed in the reav. i

Referring to the drawings, 1 represents the mountlng base' to which is suitably attached as by screws 2, all necessary mountng posts 3 and terminals 4, and holding plate 5. The mounting base may be of micarta or similar insulating material. Holding plate 5 serves asa base to which is attached relay base 6 by means of angle brackets 7 and 8. Suitably attached to the under side of relay base 6 by details 10 and 11 sa U-shaped magnet 9. A detailed descrlption of the magnetic, polar and contact structures on the upper side of relay base 6 W111 now be given. To support 12 mounted on base 6 is rigidly attached one extremity of read armature 13. -The efiective vibrat trolled b adjustable clamping means consistingo a base 14 andtop15. Clamping top 15 is suitably niched so'that reed 15 snugly fits between the under side of damp mg top 15' and'the upper side of 14. Slots 16 are provided in base 6 through which.

screws 17 pass to hold the adjustable base '14 in any desired position. lVhen 14 is moved to a desired position and the screws 17 tightened, reed 13 is clam d ,to relay base 6. The effective length ol the reed or armature will therefore comprise the portion thereofbetween the clamping point and the other extremity'extending between poles 18, 19, 20, 21 and through coil 22.: Pro

ceeding to a considerationof the cross pole construction as illustrated in Fig. 4, N and S represent respective north and south polar extremities of magnet 9. To each pole is connected two polar extensions, as- 19 and 20 to pole N, and 18 and21 to pole S. The

result in effect is tantamount toproducing two north les 19 and 20,,and two south.

poles 18 an 21. The extensions are afiixed to the poles by screws23'or in any other suitable manner. Coil 22 has a central opening, is positioned between the polar extensions, and is'sufpported at its center rtion by prongs 24 o the polar extensions m such 19, 20, and by loosening screws of the extensions by moving them as desired in slotted spaces 35. Upon adjusting them to a manner as toprevent it from interfering with the vibration of armature 13 which rojects therethroug Considering the oose contact device, 26 is a right-angled support member aflixed to the armature. The upright portion of the support'26 is apertured and loosely'supports one extremity of the tubular contact device 27. The

other end of contact device 27 is in the form of a hook eye which is linked with a similar hook eye 28 which is rigidly held by mount- 29, itself securely fastened to base 6. These 'extre 'ties of contact device 27 and terminal 28 may be compared in their contact relation to two links of a chain the up.- per link of which supports the lower one.

It. may be noted that polar extensions 18', 21 may be adjustably moved 23 to vary the position suitably fix the space relation between opture, they may positely positioned prongs 24, and the armathen be clamped in thedesired position by tightening screws 23. The strength of the flux circuits between the twosets of poles can therefore be easily and minutely varied, to vary the vibrationof the reed.

The operationof this relay will now be exlained. Upon the energization of coil 22 y a source of alternating current, reed or armature 13 will be actuated and commence contact at its extremities with support 26 and terminals .28, the vibration of the reed will cause vibration of the contact device and break such a normally closed circuit at one or both of these contacts. The control of any circuit in which contact device 27 is a link, could therefore be had by such a relay. Upon the deenergization of coil 22,

the armature ceases vibrating, and contact device27, by force of gravity will thereupon close its contacts, and the normally closed circuit is once more completed.

It is, of course, apparent that the relay could, in this manner, controlany desired circuit arrangement.

Proceeding to a consideration of the relay illustrated in Figs. 5, 6 and 7, the mounting base 1, mounting post 3, terminals 4, holding plate 5, relay base 6, angle brackets 7 and 8 and U-shaped magnet 9 are in struc ture and position substantially as described in connection with Figs. 1, 2, and 3. A

means 15 may detailed description of the magnetic, polar andcontact structures on the upper side itself rotated by knob 18, to effect such motion. Both top andbottom portions of ad- {justment means 15"aie slotted as illustrated y orifices 19,. which extend the total depth of device 15.- B. moving knob 18, therefore,

variously positioned and upon being clamped by screws 20 will fix the length of reed 13 to enable its'vibration in accordance with any desired frequency. Reed 13 is channeled, and fits into the top portion of adjustment means 15, servingto esp the means in. alignment with the reed to prevent distortion of the reeduponits being clamped in position.

' Referring to the magnetic and'polar structure, 21 and 22 are projection arms of suitable magnetic material clamped between the polar extremities of magnet 9 and base 6."

Topmost extremities of projections 21 and 22 are fastened by screws to cross member 23. It should be noted that base 6 and cross member 23 are of non-magneticmaterial, for example, brass. To'the inner sides of projections 21 -and22 are fastened arms 2 1 to which coils 25 are secured. Arms 24 ex tend beneath'coils 25 and have their extremities 26. in'space relation with cores 27 of the coils, so that the extremity of reed 13 terminates intermediate the cores and the extremities 26. The cores'27' are joined at 28 to the projections of the magnets 21 and 22, thereby completing the magnetic circuit at this joint. Coils 25 are preferably serially connected and arranged to, be eneregized by a source of alternating'current, not shown. The contact device "employed in this relay is substantially as describedhereinbefore in connection with Figs.. 1, 2, and The contact member 30 is supportedat one extremity by right-an led support 31, affixed to reed 13; The ot er extremity is loosely linked, as hereinbefore described to hooked terminal 32 which is ri' idly fixed to mounting 33, itself securely astened to base 6, 3 1 repre sents a terminal on mounting 34 to make electrical connection with an outside conductor.

The operation of the relay is as follows: Upon the energization of coils 25, reed 13 will vibrate in accordance with the frequentremities to narrow the gap therebetween.

Inasmuch as knobs 36 are ofnon-magnetic.

material, the course .of the flux circuit is not afi'ected thereby. Upon the vibration of the reed contact device will accordingly vibrate, and break its contacts with terminal 32 and support 31. If contact device 30 be assumed to normally close a circuit at said contacts, its action would tend to break the circuit at the contacts. When the coils are deenergized, the reed will cease vibrating and the intermittent breaking :of the circuit due to the vibration of the reed will accordingly stop, The electrical continuity of the circuit will thus be restored by the contact device due to the force of gravity, removing contact at its extremities. v 7

It may be noted that the reed is apertured as shown at 40 beneath the contact device I 30, to'make it lighter in weight and prevent possible interference from waves set up during vibration." C 7 a It is a matter of note that when the free end ofthe armature or reed is adjusted so that its mechanical period of vibration is the same as the riod of the alternating current through 1; e energizing coil or coils,

the armature will vibrate with the maxi-.

mum amplitude. When the amplitude is 1 such that its acceleration just exceeds that of gravity, the contacts will open, effect the operation of the relay, and control the circuit dependent for its continuity upon the normal condition of the relay. Since the amplitude required at the voice frequency is ve small, this device is sensitive to extreme y small alternating currentsi Further, it is apparent that the contacting device is free to move upon the slightest vibra tion imparted to it" throu h the supporting contacts. No friction or inding is present which would require greater amplitudes of motion to break the steady contacts obtained when the device is at rest.

What is claimedis:

1. An electromagnetic device compris n a magnet having two north and two south polar extensions forming two sets of north and south poles, azcoil positionedbetween lar extensions, an armature extendtweensaid polar extensions and through said coil, and a contact device loosely supported at one" end from said armature.

2. An electromagnetic device comprising a magnet having two north and two south polar extensions forming two sets of north and south poles, a coil "positioned between said lar extensions, an armature extending rough' said coil and adapted to be actuated uponlthe energization of said coil by a source of alternating current, and

"er-mum in spaced rename said coil and; saidpolar extensions, and a con-' mat tact device loosely supported at one end from said armature.

n ect omagnetic device comprising 7oa magnet having polar extensions forming two setsof north and south poles, an armature positioned intermediate said two sets of poles, a contact device loosely resting upon and normally connecting a plurality of terminals, one of which terminals is mounted on said armature, and means comprising a coil positioned between said sets of poles adapted when eneiized by a source of alternating current to vi rate said armature to break saidelectrical connections of said device. .7

' 4. An electromagnetic device comprising an armature, a magnet having a plurality of polar extensions concentrated at opposite sides of. said armature, two of said polar extensions on one side being of opposite polarity, two of said polar extensions on the other side being of opposite polarity, each individual one of said la'r'extensions being directly opposite a po ar extension of the opposite polarity, an alternating current "winding cooperating ,with 'said armature, and a contact device loosely engaging and electrically connecting a plurality of terminals, one of which-is mounted on said armature, whereby upon the energization of said windlng, said armature causessaid contact device to vibrate, thereby breaking the connectionbetween said terminals.

5. An electromagnetic device comprising an armature,"a magnet having a plurality of polar extensions concentrated about said armature, each 'ofvsaid olar extensions being directly opposite a po ar extension of opposite polarity, bevelled prongs at one extrem-,

ity of said extensions for supporting an alternating current windin surrounding said armature, said pron o? sions bein in space relation with said armature, said coil being located between polar extensions of opposite polarity on each side of saidarmature, and a contact device loosely v engaging and "electrically connecting a P m 3 0 v v mounted on said armature, whereby upon the energization ofsaid winding and the consequent vibration ofsaid armature, said contact device is' jostled, therebybreaking said electrical connection between the "tier-- minals.

terminals, one ,of which'is i said polar exten-v 6. A relaycomprising a magnet, an alter- I nating current winding in the 'l'nagnetic 'field thereof, an armature, means for adjusting the effective vibrating length of armature, a contact device loosely engaging and electrically connecting a series of terminals', 'being,mountedon said armature,-

whereby upon the energization of said winds ing, and the consequent vibration of said armature, said contact device s jostled, thereby the terminals; v

"T. A voice frequency relay comprisingan armature, adjustment means iorcoiitrollin the length of the vibrating portion thereo the remaining portion being stidened by said.

adjustment means and arigid clamping support, circuit controlling means'including a contact device loosely supported at each end by a terminal, one of which is mounted :on said armature, and means comprising a coil ada tedto be energized by a source 0 alternating current to cause said armature to vibrate in accordance with adesired, irequency, to break said contacts. 4

8. An electromagnetic device comprising a magnet, a coil, an armature cooperating with saidcoil and magnet, said armature being adapted to be variably controlled to,

ibrate at a desired frequency, a contact device one end of which is loosely suspended from and makes electrical contact with a stationary terminal and the other end is loosely suspended from and makes electrical contact with a terminal mounted on said armature, whereby upon the energization of said coil, and the consequent vibration of said armature, motion is imparted to said contact device whereby said electrical contacts are broken. 7

9. An electromagnetic device comprising a magnet, an armature in the field of said magnet, an alternating current winding in operative relation to said magnet having a plurality of polar extensions of opposite polarity on each side of said armature, said polar extensions of like polarity being diagonally opposed to each other and positioned on said armature, said polar extensions containing slots for adjusting their space relation with. said armature, and a loose conarmature, said opposite sides of amass? one end from a tact .device: supported at at the other end stationary terminal and from atermlnal mounted on and vibrating with said armature.

10. An electromagnetic device comprising i the frequency of the applied current, and

a loose contact device supported at one end from a stationary terminal and at the other I end from 'a terminal mounted on and vibrating with said armature. I

11. A relay comprising a magnet, an armature in the field of said magnet, magnetic circuits including a portion of said armature,

as part thereof, means for energizing said magnetic circuits by alternating current whereby said armature may be caused to vibrate in accordance with the frequency of said current, a loose contactdevice controlled by said armature, a stationary terminal on said armature, a second stationary terminal positioned in spaced relation to said armature, a support having a hook eye at the end thereof mounted on said second terminal, said contact device having a projection integral therewith loosely resting in an orifice of said first terminal, the other end of said contact device being a hook eye loosely linked to the eye of said.

support, whereby said contact device is coupled to vibrate in accordance with the frequency of said applied current without binding at its contacting extremities. y

In witness whereof, I hereunto subscribe my name this 6th day of September A. 1).,

I EDWARD J. PRATT. 

